EMP Bombs can be detonated to deal massive amounts of EMP damage, and can crit for even higher damage. They are single-use and can be purchased from most standard vendors. All EMP Bombs have a range of 15 meters, regardless of level.
To use an EMP Bomb, simply place it in the area you would like to detonate it in and it will explode after a delay of a few seconds. The detonation will not damage you or your group. You can only have one bomb placed at a time - if you place another before the first has detonated, your first one will simply vanish.